1 files changed, 587 insertions, 0 deletions
diff --git a/dom/base/nsContentList.h b/dom/base/nsContentList.h
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--- /dev/null
+++ b/dom/base/nsContentList.h
@@ -0,0 +1,587 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * nsBaseContentList is a basic list of content nodes; nsContentList
+ * is a commonly used NodeList implementation (used for
+ * getElementsByTagName, some properties on nsIDOMHTMLDocument, etc).
+ */
+
+#ifndef nsContentList_h___
+#define nsContentList_h___
+
+#include "mozilla/Attributes.h"
+#include "nsContentListDeclarations.h"
+#include "nsISupports.h"
+#include "nsTArray.h"
+#include "nsString.h"
+#include "nsIHTMLCollection.h"
+#include "nsIDOMNodeList.h"
+#include "nsINodeList.h"
+#include "nsStubMutationObserver.h"
+#include "nsIAtom.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsNameSpaceManager.h"
+#include "nsWrapperCache.h"
+#include "nsHashKeys.h"
+#include "mozilla/HashFunctions.h"
+#include "mozilla/dom/NameSpaceConstants.h"
+
+namespace mozilla {
+namespace dom {
+class Element;
+} // namespace dom
+} // namespace mozilla
+
+
+class nsBaseContentList : public nsINodeList
+{
+public:
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+
+  // nsIDOMNodeList
+  NS_DECL_NSIDOMNODELIST
+
+  // nsINodeList
+  virtual int32_t IndexOf(nsIContent* aContent) override;
+  virtual nsIContent* Item(uint32_t aIndex) override;
+
+  uint32_t Length() const { 
+    return mElements.Length();
+  }
+
+  NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS(nsBaseContentList)
+
+  void AppendElement(nsIContent *aContent)
+  {
+    mElements.AppendElement(aContent);
+  }
+  void MaybeAppendElement(nsIContent* aContent)
+  {
+    if (aContent)
+      AppendElement(aContent);
+  }
+
+  /**
+   * Insert the element at a given index, shifting the objects at
+   * the given index and later to make space.
+   * @param aContent Element to insert, must not be null
+   * @param aIndex Index to insert the element at.
+   */
+  void InsertElementAt(nsIContent* aContent, int32_t aIndex)
+  {
+    NS_ASSERTION(aContent, "Element to insert must not be null");
+    mElements.InsertElementAt(aIndex, aContent);
+  }
+
+  void RemoveElement(nsIContent *aContent)
+  {
+    mElements.RemoveElement(aContent);
+  }
+
+  void Reset() {
+    mElements.Clear();
+  }
+
+  virtual int32_t IndexOf(nsIContent *aContent, bool aDoFlush);
+
+  virtual JSObject* WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto)
+    override = 0;
+
+  void SetCapacity(uint32_t aCapacity)
+  {
+    mElements.SetCapacity(aCapacity);
+  }
+protected:
+  virtual ~nsBaseContentList();
+
+  /**
+   * To be called from non-destructor locations (e.g. unlink) that want to
+   * remove from caches.  Cacheable subclasses should override.
+   */
+  virtual void RemoveFromCaches()
+  {
+  }
+
+  nsTArray< nsCOMPtr<nsIContent> > mElements;
+};
+
+
+class nsSimpleContentList : public nsBaseContentList
+{
+public:
+  explicit nsSimpleContentList(nsINode* aRoot) : nsBaseContentList(),
+                                                 mRoot(aRoot)
+  {
+  }
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(nsSimpleContentList,
+                                           nsBaseContentList)
+
+  virtual nsINode* GetParentObject() override
+  {
+    return mRoot;
+  }
+  virtual JSObject* WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto) override;
+
+protected:
+  virtual ~nsSimpleContentList() {}
+
+private:
+  // This has to be a strong reference, the root might go away before the list.
+  nsCOMPtr<nsINode> mRoot;
+};
+
+/**
+ * Class that's used as the key to hash nsContentList implementations
+ * for fast retrieval
+ */
+struct nsContentListKey
+{
+  // We have to take an aIsHTMLDocument arg for two reasons:
+  // 1) We don't want to include nsIDocument.h in this header.
+  // 2) We need to do that to make nsContentList::RemoveFromHashtable
+  //    work, because by the time it's called the document of the
+  //    list's root node might have changed.
+  nsContentListKey(nsINode* aRootNode,
+                   int32_t aMatchNameSpaceId,
+                   const nsAString& aTagname,
+                   bool aIsHTMLDocument)
+    : mRootNode(aRootNode),
+      mMatchNameSpaceId(aMatchNameSpaceId),
+      mTagname(aTagname),
+      mIsHTMLDocument(aIsHTMLDocument),
+      mHash(mozilla::AddToHash(mozilla::HashString(aTagname), mRootNode,
+                               mMatchNameSpaceId, mIsHTMLDocument))
+  {
+  }
+
+  nsContentListKey(const nsContentListKey& aContentListKey)
+    : mRootNode(aContentListKey.mRootNode),
+      mMatchNameSpaceId(aContentListKey.mMatchNameSpaceId),
+      mTagname(aContentListKey.mTagname),
+      mIsHTMLDocument(aContentListKey.mIsHTMLDocument),
+      mHash(aContentListKey.mHash)
+  {
+  }
+
+  inline uint32_t GetHash(void) const
+  {
+    return mHash;
+  }
+  
+  nsINode* const mRootNode; // Weak ref
+  const int32_t mMatchNameSpaceId;
+  const nsAString& mTagname;
+  bool mIsHTMLDocument;
+  const uint32_t mHash;
+};
+
+/**
+ * LIST_UP_TO_DATE means that the list is up to date and need not do
+ * any walking to be able to answer any questions anyone may have.
+ */
+#define LIST_UP_TO_DATE 0
+/**
+ * LIST_DIRTY means that the list contains no useful information and
+ * if anyone asks it anything it will have to populate itself before
+ * answering.
+ */
+#define LIST_DIRTY 1
+/**
+ * LIST_LAZY means that the list has populated itself to a certain
+ * extent and that that part of the list is still valid.  Requests for
+ * things outside that part of the list will require walking the tree
+ * some more.  When a list is in this state, the last thing in
+ * mElements is the last node in the tree that the list looked at.
+ */
+#define LIST_LAZY 2
+
+/**
+ * Class that implements a live NodeList that matches Elements in the
+ * tree based on some criterion.
+ */
+class nsContentList : public nsBaseContentList,
+                      public nsIHTMLCollection,
+                      public nsStubMutationObserver
+{
+public:
+  NS_DECL_ISUPPORTS_INHERITED
+
+  /**
+   * @param aRootNode The node under which to limit our search.
+   * @param aMatchAtom An atom whose meaning depends on aMatchNameSpaceId.
+   *                   The special value "*" always matches whatever aMatchAtom
+   *                   is matched against.
+   * @param aMatchNameSpaceId If kNameSpaceID_Unknown, then aMatchAtom is the
+   *                          tagName to match.
+   *                          If kNameSpaceID_Wildcard, then aMatchAtom is the
+   *                          localName to match.
+   *                          Otherwise we match nodes whose namespace is
+   *                          aMatchNameSpaceId and localName matches
+   *                          aMatchAtom.
+   * @param aDeep If false, then look only at children of the root, nothing
+   *              deeper.  If true, then look at the whole subtree rooted at
+   *              our root.
+   */  
+  nsContentList(nsINode* aRootNode,
+                int32_t aMatchNameSpaceId,
+                nsIAtom* aHTMLMatchAtom,
+                nsIAtom* aXMLMatchAtom,
+                bool aDeep = true);
+
+  /**
+   * @param aRootNode The node under which to limit our search.
+   * @param aFunc the function to be called to determine whether we match.
+   *              This function MUST NOT ever cause mutation of the DOM.
+   *              The nsContentList implementation guarantees that everything
+   *              passed to the function will be IsElement().
+   * @param aDestroyFunc the function that will be called to destroy aData
+   * @param aData closure data that will need to be passed back to aFunc
+   * @param aDeep If false, then look only at children of the root, nothing
+   *              deeper.  If true, then look at the whole subtree rooted at
+   *              our root.
+   * @param aMatchAtom an atom to be passed back to aFunc
+   * @param aMatchNameSpaceId a namespace id to be passed back to aFunc
+   * @param aFuncMayDependOnAttr a boolean that indicates whether this list is
+   *                             sensitive to attribute changes.
+   */  
+  nsContentList(nsINode* aRootNode,
+                nsContentListMatchFunc aFunc,
+                nsContentListDestroyFunc aDestroyFunc,
+                void* aData,
+                bool aDeep = true,
+                nsIAtom* aMatchAtom = nullptr,
+                int32_t aMatchNameSpaceId = kNameSpaceID_None,
+                bool aFuncMayDependOnAttr = true);
+
+  // nsWrapperCache
+  using nsWrapperCache::GetWrapperPreserveColor;
+  virtual JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
+protected:
+  virtual ~nsContentList();
+
+  virtual JSObject* GetWrapperPreserveColorInternal() override
+  {
+    return nsWrapperCache::GetWrapperPreserveColor();
+  }
+public:
+
+  // nsIDOMHTMLCollection
+  NS_DECL_NSIDOMHTMLCOLLECTION
+
+  // nsBaseContentList overrides
+  virtual int32_t IndexOf(nsIContent *aContent, bool aDoFlush) override;
+  virtual int32_t IndexOf(nsIContent* aContent) override;
+  virtual nsINode* GetParentObject() override
+  {
+    return mRootNode;
+  }
+
+  virtual nsIContent* Item(uint32_t aIndex) override;
+  virtual mozilla::dom::Element* GetElementAt(uint32_t index) override;
+  virtual mozilla::dom::Element*
+  GetFirstNamedElement(const nsAString& aName, bool& aFound) override
+  {
+    mozilla::dom::Element* item = NamedItem(aName, true);
+    aFound = !!item;
+    return item;
+  }
+  virtual void GetSupportedNames(nsTArray<nsString>& aNames) override;
+
+  // nsContentList public methods
+  uint32_t Length(bool aDoFlush);
+  nsIContent* Item(uint32_t aIndex, bool aDoFlush);
+  mozilla::dom::Element*
+  NamedItem(const nsAString& aName, bool aDoFlush);
+
+  // nsIMutationObserver
+  NS_DECL_NSIMUTATIONOBSERVER_ATTRIBUTECHANGED
+  NS_DECL_NSIMUTATIONOBSERVER_CONTENTAPPENDED
+  NS_DECL_NSIMUTATIONOBSERVER_CONTENTINSERTED
+  NS_DECL_NSIMUTATIONOBSERVER_CONTENTREMOVED
+  NS_DECL_NSIMUTATIONOBSERVER_NODEWILLBEDESTROYED
+  
+  static nsContentList* FromSupports(nsISupports* aSupports)
+  {
+    nsINodeList* list = static_cast<nsINodeList*>(aSupports);
+#ifdef DEBUG
+    {
+      nsCOMPtr<nsINodeList> list_qi = do_QueryInterface(aSupports);
+
+      // If this assertion fires the QI implementation for the object in
+      // question doesn't use the nsINodeList pointer as the nsISupports
+      // pointer. That must be fixed, or we'll crash...
+      NS_ASSERTION(list_qi == list, "Uh, fix QI!");
+    }
+#endif
+    return static_cast<nsContentList*>(list);
+  }
+
+  bool MatchesKey(const nsContentListKey& aKey) const
+  {
+    // The root node is most commonly the same: the document.  And the
+    // most common namespace id is kNameSpaceID_Unknown.  So check the
+    // string first.  Cases in which whether our root's ownerDocument
+    // is HTML changes are extremely rare, so check those last.
+    NS_PRECONDITION(mXMLMatchAtom,
+                    "How did we get here with a null match atom on our list?");
+    return
+      mXMLMatchAtom->Equals(aKey.mTagname) &&
+      mRootNode == aKey.mRootNode &&
+      mMatchNameSpaceId == aKey.mMatchNameSpaceId &&
+      mIsHTMLDocument == aKey.mIsHTMLDocument;
+  }
+
+  /**
+   * Sets the state to LIST_DIRTY and clears mElements array.
+   * @note This is the only acceptable way to set state to LIST_DIRTY.
+   */
+  void SetDirty()
+  {
+    mState = LIST_DIRTY;
+    Reset();
+  }
+
+protected:
+  /**
+   * Returns whether the element matches our criterion
+   *
+   * @param  aElement the element to attempt to match
+   * @return whether we match
+   */
+  bool Match(mozilla::dom::Element *aElement);
+  /**
+   * See if anything in the subtree rooted at aContent, including
+   * aContent itself, matches our criterion.
+   *
+   * @param  aContent the root of the subtree to match against
+   * @return whether we match something in the tree rooted at aContent
+   */
+  bool MatchSelf(nsIContent *aContent);
+
+  /**
+   * Populate our list.  Stop once we have at least aNeededLength
+   * elements.  At the end of PopulateSelf running, either the last
+   * node we examined is the last node in our array or we have
+   * traversed the whole document (or both).
+   *
+   * @param aNeededLength the length the list should have when we are
+   *        done (unless it exhausts the document)   
+   */
+  void PopulateSelf(uint32_t aNeededLength);
+
+  /**
+   * @param  aContainer a content node which must be a descendant of
+   *         mRootNode
+   * @return true if children or descendants of aContainer could match our
+   *                 criterion.
+   *         false otherwise.
+   */
+  bool MayContainRelevantNodes(nsINode* aContainer)
+  {
+    return mDeep || aContainer == mRootNode;
+  }
+
+  /**
+   * Remove ourselves from the hashtable that caches commonly accessed
+   * content lists.  Generally done on destruction.
+   */
+  void RemoveFromHashtable();
+  /**
+   * If state is not LIST_UP_TO_DATE, fully populate ourselves with
+   * all the nodes we can find.
+   */
+  inline void BringSelfUpToDate(bool aDoFlush);
+
+  /**
+   * To be called from non-destructor locations that want to remove from caches.
+   * Needed because if subclasses want to have cache behavior they can't just
+   * override RemoveFromHashtable(), since we call that in our destructor.
+   */
+  virtual void RemoveFromCaches() override
+  {
+    RemoveFromHashtable();
+  }
+
+  nsINode* mRootNode; // Weak ref
+  int32_t mMatchNameSpaceId;
+  nsCOMPtr<nsIAtom> mHTMLMatchAtom;
+  nsCOMPtr<nsIAtom> mXMLMatchAtom;
+
+  /**
+   * Function to use to determine whether a piece of content matches
+   * our criterion
+   */
+  nsContentListMatchFunc mFunc;
+  /**
+   * Cleanup closure data with this.
+   */
+  nsContentListDestroyFunc mDestroyFunc;
+  /**
+   * Closure data to pass to mFunc when we call it
+   */
+  void* mData;
+  /**
+   * The current state of the list (possible values are:
+   * LIST_UP_TO_DATE, LIST_LAZY, LIST_DIRTY
+   */
+  uint8_t mState;
+
+  // The booleans have to use uint8_t to pack with mState, because MSVC won't
+  // pack different typedefs together.  Once we no longer have to worry about
+  // flushes in XML documents, we can go back to using bool for the
+  // booleans.
+  
+  /**
+   * True if we are looking for elements named "*"
+   */
+  uint8_t mMatchAll : 1;
+  /**
+   * Whether to actually descend the tree.  If this is false, we won't
+   * consider grandkids of mRootNode.
+   */
+  uint8_t mDeep : 1;
+  /**
+   * Whether the return value of mFunc could depend on the values of
+   * attributes.
+   */
+  uint8_t mFuncMayDependOnAttr : 1;
+  /**
+   * Whether we actually need to flush to get our state correct.
+   */
+  uint8_t mFlushesNeeded : 1;
+  /**
+   * Whether the ownerDocument of our root node at list creation time was an
+   * HTML document.  Only needed when we're doing a namespace/atom match, not
+   * when doing function matching, always false otherwise.
+   */
+  uint8_t mIsHTMLDocument : 1;
+
+#ifdef DEBUG_CONTENT_LIST
+  void AssertInSync();
+#endif
+};
+
+/**
+ * A class of cacheable content list; cached on the combination of aRootNode + aFunc + aDataString
+ */
+class nsCacheableFuncStringContentList;
+
+class MOZ_STACK_CLASS nsFuncStringCacheKey {
+public:
+  nsFuncStringCacheKey(nsINode* aRootNode,
+                       nsContentListMatchFunc aFunc,
+                       const nsAString& aString) :
+    mRootNode(aRootNode),
+    mFunc(aFunc),
+    mString(aString)
+    {}
+
+  uint32_t GetHash(void) const
+  {
+    uint32_t hash = mozilla::HashString(mString);
+    return mozilla::AddToHash(hash, mRootNode, mFunc);
+  }
+
+private:
+  friend class nsCacheableFuncStringContentList;
+
+  nsINode* const mRootNode;
+  const nsContentListMatchFunc mFunc;
+  const nsAString& mString;
+};
+
+// aDestroyFunc is allowed to be null
+// aDataAllocator must always return a non-null pointer
+class nsCacheableFuncStringContentList : public nsContentList {
+public:
+  virtual ~nsCacheableFuncStringContentList();
+
+  bool Equals(const nsFuncStringCacheKey* aKey) {
+    return mRootNode == aKey->mRootNode && mFunc == aKey->mFunc &&
+      mString == aKey->mString;
+  }
+
+#ifdef DEBUG
+  enum ContentListType {
+    eNodeList,
+    eHTMLCollection
+  };
+  ContentListType mType;
+#endif
+
+protected:
+  nsCacheableFuncStringContentList(nsINode* aRootNode,
+                                   nsContentListMatchFunc aFunc,
+                                   nsContentListDestroyFunc aDestroyFunc,
+                                   nsFuncStringContentListDataAllocator aDataAllocator,
+                                   const nsAString& aString) :
+    nsContentList(aRootNode, aFunc, aDestroyFunc, nullptr),
+    mString(aString)
+  {
+    mData = (*aDataAllocator)(aRootNode, &mString);
+    MOZ_ASSERT(mData);
+  }
+
+  virtual void RemoveFromCaches() override {
+    RemoveFromFuncStringHashtable();
+  }
+  void RemoveFromFuncStringHashtable();
+
+  nsString mString;
+};
+
+class nsCacheableFuncStringNodeList
+  : public nsCacheableFuncStringContentList
+{
+public:
+  nsCacheableFuncStringNodeList(nsINode* aRootNode,
+                                nsContentListMatchFunc aFunc,
+                                nsContentListDestroyFunc aDestroyFunc,
+                                nsFuncStringContentListDataAllocator aDataAllocator,
+                                const nsAString& aString)
+    : nsCacheableFuncStringContentList(aRootNode, aFunc, aDestroyFunc,
+                                       aDataAllocator, aString)
+  {
+#ifdef DEBUG
+    mType = eNodeList;
+#endif
+  }
+
+  virtual JSObject* WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto) override;
+
+#ifdef DEBUG
+  static const ContentListType sType;
+#endif
+};
+
+class nsCacheableFuncStringHTMLCollection
+  : public nsCacheableFuncStringContentList
+{
+public:
+  nsCacheableFuncStringHTMLCollection(nsINode* aRootNode,
+                                      nsContentListMatchFunc aFunc,
+                                      nsContentListDestroyFunc aDestroyFunc,
+                                      nsFuncStringContentListDataAllocator aDataAllocator,
+                                      const nsAString& aString)
+    : nsCacheableFuncStringContentList(aRootNode, aFunc, aDestroyFunc,
+                                       aDataAllocator, aString)
+  {
+#ifdef DEBUG
+    mType = eHTMLCollection;
+#endif
+  }
+
+  virtual JSObject* WrapObject(JSContext *cx, JS::Handle<JSObject*> aGivenProto) override;
+
+#ifdef DEBUG
+  static const ContentListType sType;
+#endif
+};
+
+#endif // nsContentList_h___